1. Field of the Invention
The present invention relates to a method for manufacturing a one side resin sealing type semiconductor device in which a circuit board such as a BGA (Ball Grid Array) is used, and also relates to a carrier frame used for manufacturing such a one side resin sealing type semiconductor device.
2. Description of Related Art
An over molded BGA type semiconductor device is manufactured in such a manner that a semiconductor element is mounted on a printed board, and one of the surfaces of the printed board on which the semiconductor element is mounted is sealed with resin, and then solder balls are attached onto the other surface of the board. According to the method of manufacturing a BGA type semiconductor device of the prior art, a printed board of a large size, on both surfaces of which the predetermined wiring patterns are provided (these wiring patterns on the both surfaces being connected by through-hole patterns), is cut into several rectangular pieces, and each of the thus obtained rectangular printed boards 5 is conveyed to the processes of mounting a semiconductor element, bonding wires, sealing with resin and attaching solder balls. In this way, the product of the semiconductor device is manufactured.
The above-mentioned method in which the rectangular printed board is conveyed to each process for manufacturing BGA type semiconductor device is advantageous, because it is possible to utilize a common manufacturing apparatus of semiconductor devices in which a lead frame is used. However, when a rectangular printed board is used, a problem may be encountered, in which a large part of the printed board must be wasted.
In the case where a plurality of BGAs are manufactured using a rectangular printed board, the semiconductor elements are mounted on one of the surfaces of the printed board and subjected to resin molding, and then external terminals such as solder balls are joined onto the other surface of the printed board. After that, the printed board is cut off to obtain several BGAs. Accordingly, the area of the printed board outside the cutting position is not used for the product of the semiconductor device, so that material of the periphery of the rectangular printed board is wasted. Beside, when the rectangular printed board is made of a printed board of a large size, it is necessary to provide a flap for cutting of the printed board. Therefore, material of the printed board corresponding to the flap for cutting is wasted in the process of making the printed board.
In order to avoid the aforementioned waste of material of the printed board, the following method may be adopted. The base board is individually formed, being separated into each piece of the product size, and each piece is conveyed one by one so that a semiconductor element is mounted on each base board and then each base board is subjected to resin molding. However, it takes time and labor to handle a printed board that has been divided into individual pieces. Further, it is impossible to utilize a common semiconductor manufacturing apparatus in which a lead frame is utilized.